Effects of input power, gas flow rate and hydrogen concentration on Cu film deposition by a radio frequency driven non-thermal atmospheric pressure plasma jet

A radio frequency driven non-thermal atmospheric plasma jet with a copper wire used as precursor is applied for Cu film deposition. The effects of input power, hydrogen concentration (C-H2) and gas flow rate on the discharge parameters, and eventually on film deposition rate and its properties are investigated. The results show that, besides the plasma gas temperature (T-g), the discharge current flowing through the copper wire (I-fc) is also a key parameter for Cu film deposition. With increasing input power, both T-g and I-fc increase, which both facilitate the increase of film deposition rate, surface roughness and particle size on the film. Higher gas flow rate leads to lower T-g, and results in the decrease of the deposition rate, surface roughness and particle size. The influences of C-H2 in plasma forming gas on Cu film deposition have dual characters, due to the increase in the T-g and decease in the I-fc with C-H2 increase. When the C-H2 is below1.6 parts per thousand, increasing C-H2 has promotion role on the film deposition rate increase and particle size enlargement on the film, and the results reverse as the C-H2 is above 1.6 parts per thousand.